Henning e



' M. smmmum. ELEGWNB CIRCUIT TESTER. .MPLNZATIUN FILED m. 12, 19:9.

Patented Sept. 9, 1919.

ELECTRIC-CIRCUIT *TES'IER.

Application filed February 12,

To an ar/20m a may concern:

' working condition,

Be it known that I, Hnnnrne R. SJO- LANDER, a citizen of the United States, residing at Ishpeming, in the county of Marquette and State of Michigan, have invented certain new and useful Improvements in Electric-Circuit Testers, lowing is a specification, reference being had to the accompanying drawings, forming a part thereof.

This invention relates to means for testing a plurality of associated electric circuits especially when they are arranged with a common return or ground connection as in the case'of the ignition circuit of an automobile or any multiple cylinder internal combustion engine. The invention provides means enabling the driver or engineer to determine at any time whether the spark plugsv and the like of the several cylinders are in good and to detect and locate afault .in any one of such spark plugs or other ignition devices by cutting out of operation all the cylinders but one, and'selecting any such one to be run alone for observing its operation or noting any defect of operation apart from the remainder. The inven tion consists in the" elements and features of construction and their combination hereinafter described and shown in the drawings as indicated-by the claims.

In the drawings:

Figure 1 is a face view of an instrument embodying this invention.

Fig. 2 is a section taken as indicated at line 2-2on Fig. 1.

Fig. 3-is a face view of the insulating mount in which the'electrodes forming indicating spark gaps are carried.

Fi 4: is a rear face view of the cover or shiel member provided withapertures for disclosing the indicating sparks in the spark aps.

Fig. 5 is a detail section taken as indicated at line 5-5 on Figure. 1.

Fig. 6 is a detail section taken similarly to Fig. 5 but showing the parts differently adjusted sothat the aperture or window of the shield or covermember is out of regist ation with the spark gaps.

Fig. I E detail section taken'as indicated at line 7-( on Fig. 1..

Specification of Letters .Patent.

of which the fol-' spark between Patented Sept. 91, 1919.

1919. Serial no. 276,590.

Fig. 8 is a wiring diagram for the device embodying this invention. As illustrated in the drawings this device is particularly designed for use with an internal combustion engine and such use is suggested by the wiring diagram on Fig. 8; but it may be understood that the principles involved will apply equally well to a circuit tester especially arranged for some other electrical devices. The structure illustrated consists of a base or mount, A, of insulating material in which there are secured a plurality of pairs of electrodes, B and C, provided at the rear side of the mount, A, with connector sleeves, B and C, respectively, to receive wires, of the various circuits to be tested. As applied to an internal combustion engine, each pair of electrodes, B and C, is plugs of an engine, preferably in the line running from the distributer indicated in Fig. 8 at E to the spark plugs, each of which is denoted by the letter, F,'in said diagram. Thus, when the engine is running properly, there will be a spark formed between each pair of electrodes, B and C, simultaneously with the firing of the particular cylinder whose spark plug is connected in series with a pair' of electrodes, and the presence of such energy-indicating these electrodes will advise the engineer or driver that the circuit at least is complete from the distributor to the spark plug.

However, if it should happen that the spark plug of any cylinder has become fouled with soot or oil, or otherwise shortcircuited, the cylinder would not fire properly, although the current would pars r. :n the distributor to the spark plug and would be so indicated between electrodes, B and C, of that line. For detecting such faults of the spark plugs, therefore, another method is adopted, namely the grounding of all the spark plugs but one, selecting varlous groupings of the plugs in this way, thus causing the engine to run on one cylinder alone until the faulty cylinder is definitely located.

is provided for it, also in the form of a 011'- cular disk, having a series of apertures ar 4 connected in series with one of the spark ranged to register with the pairs of electrodes, B and C, so as to serve as sight windows through which the sparks at such electrodes may be observed, and each of these apertures is lined with a metallic tube, H, having at its outer end a contact lug, H extending radially inward from the si ht aperture or window formed by the tube, H.

At the other end of each tube, H, a cont/M241? lug, H extends in circumferential direction on the rear face of the cover member, G, for electrical contact with oneof the electrodes in the base or mount, A. By this means each spark plug circuit is provided with a contact, H oh the face of the cover member, G, over which there is rotatively mounted a multiple armed contact member, J, electrically connected through its pivot, with a ground wire, L, leading to the same common retugngor ground connection, which is prpvideii rpr the spark plug circuit.

Theinember, J, has a number of radial arms, J each extending for engagement with one of the contact lugs, H but num-F bering one less than the total number of such lugs, H so that, at any time, the member, J, may serve to ground all of the spark plug circuits except one. By rotation upon its pivot, K, which is centrally located respect tothe circular arrangement of the contacts, H each of said contacts in turn may be left ungrounded leaving the engine to operate upon the spark plug connected to such ungrounded contact, H and permitting the engineer to observe the action-of .each cylinder individually. Each of the windows formed by the tubes, H, may have associated with it on the face of the cover member, G, a numeral corresponding to a particular cylinder of the engine, to which the wires leading from electrodes B and O, are connected, and, if desired, the rotatable grounding member, J, may carry in place of its-omitted contact arm, a small pointer or arrow, M, which will'call attention to the window andthe numeral associated therewith indicating the particular cylinder being tested for any adjusted position of the grounding member. For throwing the device out of use,'said grounding member, J, may be set at any intermediate position with its:arms, J extending into the spaces between adj acentcontajcts, Hfiso as to form no electrical connection therewith; If desired, the cover member, G, may also be rotatable upon the pivot, K, through a short range for moving its windows, formed by the tube, H, out of registration with the spark gaps, If the device is mounted on the dash board or instrument board of an automobile, it may be preferable not to have the spark gaps in opcration, tending to distract the drivers at- 'tention when the car is actually running.

contact lugs or plates H, on the rear face \each spark gap and eliminating the spark thel'cili so long as this metallic circuit is provided by such positioning of the cover plate, Gr. FO1 retaining said cover at either limit movement, a spring detent, N, may be set in the face of the mount, A, as indicated in Figs. 3, Land 7, engaging depressions, O and P, respectively at opposite'ends of the groove, Q, which represents the range of such rotative adjustment of the cover.

The grounding member, J, being of more or less resilient material with its central portion spaced away from the shield or cover member, G, and retained under the head of the pivot member, K, will provide suiiicient pressure for good electrical contact between feach of its arms, J and the lugs, H and at the same time press the shield or cover, G, against the base or mount, A, insuring good "contact of the lugs, H with one or both of electrodes, B and C, of each pair. By reason of its resilience, the grounding member, J, frictionally engages the surface of the shield or cover, G, and also the contacts, H and the initial rotation of said grounding member for engagement with said contacts will cause the limited rotation of the shield, G, required for moving its apertures into registration with the spark gaps at electrodes, B and C. Continued rotary adjustment of the member, J, in the same direction will cause no further rotation of the shield after engagement of its detent, N, with depression, 0, but when the member, J, hasbeen successively adjusted for testing all the cylinders, a slight reverse movement of said member sufficient to carry its arms out of contact with the lugs, H and into registration with the spaces between them will also shift the shield, G, to position fO1"COV81.l11g the spark gaps, with shunt plates, H bridging them and with the detent, N, in depression, P.

I claim:

1. In combination with a plurality of electric circuits having a common return or ground connection, a testing device comprising an insulated mount carrying a series of contacts respectively wired to the individual circuits, and a grounded contact mem ber formed to engage simultaneously?" definite number but not all of said contacts, said contact member and the carrying mount be ing relatively adjustable for selectively grounding said circuits in different groups to permit observing the operation of the remainder. and detecting faults therein.

2. In the combipation set out in claim .1, said grounded contact member being also adjustable out, ofengagement with all the contacts simultaneously to allow normal operation of the circuits.

l prising a series of 3. In the combination set out-in claim 1,

said contacts being symmetrically disposed upon the carrying mount about an axis and the relative adjustment of the mount and contact member being a rotation about such axls. 4. In the combination set out in claim 1, said contacts being arranged in a circle on the faceqf the mount and the grounded member being pivoted at the center of" the circle.

5. In the combination set out in claim 1, said contacts being arranged in a circle on the face of the mount and the grounded mem her being pivoted at the center of the circle and having contact arms numbering one less than the contacts on said mount, whereby rotative adjustment of said member upon its pivot will ground any selected group of said circuits omitting one.

6. In combination with a plurality of electric circuits having a common return or ground connection; a testing device comspaced visible indicators, in series with one of said formed with a each. connected circuits, a shield or cover series of apertures spaced to register with said indicators respectively, the shield being mounted for limited bodily movement for shifting its apertures into such registration and disclosing the indicators, together with a series of spaced contacts on the cover, each "connected to one of the circuits and a grounded contact member having a plurality of arms spaced for simultaneous engagement with the said contacts or with the spaces between them and mounted for movement over said shield or cover in frictional engagement therewith, whereby an initial movement of said grounded member will carry said apertures into registration with the indicators.

- circular 7 In the combination set out in claim 6, said series of indicators being disposed in arrangement with the shield or cover provided with apertures and contacts both located in circles concentric with that of the indicators, the grounded member and the shield being both mounted for rotatlve adjustment about the common axis of said circles.

8. In combination with a plurality of electric circuits having a common return or ground connection, a testing device, com prising a series of contacts, respectively wired to theindividual circuits, a manually operable member and grounded contact means actuated thereby for simultaneously engaging said series of contacts, said member being adjustable for thus grounding the individual circuits in difierent groups, to permit observing the remainder in operation for locating faults therein.

9. In the combination setout in claim 1, said contacts being circularly disposed on 'with any group of a definite number, but not all of the mount with spaces between adjacent contacts and the contact member having arms numberingone less than said contacts and radiating from the center of such circular arrangement, spaced'for simultaneous engagement of each arm with one of the contacts, and rotatively adjustable at will about the center for registering the arms contacts omitting one, or for registration of all the arms with the spaces between contacts.

10. In combination with a plurality of electric circuits, a testing device comprising a series of visible indicators, each connected in series with one of said circuits, a cover member or shield having a series of apertures through each of which one of said indicators is visible,the shield being movable for shifting said apertures out of-registration with the indicators, each indicator having a pair of contacts connected to its in coming and outgoing leads respectively, and a shunt plate on the shield member for each pair of such contacts positioned to engage them when the shield apertures are moved out of registration with the indicators.

11. In combination with an internal combustion engine, a testing device for the ignition comprising a series of electrodes driver, and means connectingeach pair in series with one of the engine spark plugs together with a shield member having a series of apertures, with one pair of said electrodes, said shield being movable out of registration with said electrodes, and a series of contact plates associated with the shield in positions to engage and shunt the respective pairs of electrodes when the shield is so shifted.

12. In combination with a plurality of electric circuits having a common return or ground connection, a testing device comprising an insulated mount carrying a series of visible indicators, each connected in, series with one of said circuits, an electric contact associated with each indicator and connected to its circuit, and a grounded contact member formed to engage simultaneously a definite number, but not all, of said indicator contacts and movable at will for thus groundeach arranged to register in g the circuits in different groups for locating faults.

13. In combination with a plurality of el'ectrlc circuits, a testing device comprising a series of visible indicators, each connected in series with one of said circuits, a cover member or shield having aseries of apertures througheach of which one of said indicators is visible, the shield being movable for shifting said apertures out of regisindicator contacts through maintain electric connection with one of said out the range of movement of said shield, together with a grounded contact member formed to engage 5 simultaneously a definite number, but not all of said contacts on the shield and moveble relatively thereto for se leetively grounding the circuits in difierent groups for 'detecting faults therein.

In testimony whereof, I have hereunto '11 set my hand at Chicago, Illinois; this 7th dayof February, 1919.

HENNING R. SJOLANDER. 

